Equity Investments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 459		$ 459		$ 422
Equity in earnings of unconsolidated affiliates	$ 12	$ 12	$ 35	$ 36
Four Hospitals in Las Vegas, Nevada [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	27.50%		27.50%
One Hospital in Las Vegas, Nevada [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	26.10%		26.10%
Three Hospitals in Macon Georgia, [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	38.00%		38.00%
HealthTrust [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	24.60%		24.60%